This invention relates generally to the field of electro-optical devices and more specifically to a method and system for gating a sensor.
Night vision devices enable a user to view a scene with little or no visible ambient light. Law enforcement and military personnel often use night vision devices during night time surveillance and maneuvers. Night vision devices typically employ an image intensifier tube that amplifies light in order to provide an enhanced image to the user.
Gated night vision devices, however, are susceptible to interference associated with oscillatory ambient light, which causes bright flashes of light that interfere with the viewed image. Some systems attempt to avoid the interference by determining the frequency of the ambient light and then using a gating frequency that avoids the interference. A disadvantage of these systems is that interference may occur if the frequency of the ambient light changes. Additionally, these systems may experience interference if the ambient light includes multiple frequencies or does not follow a regular pattern. Consequently, avoiding interference has posed challenges for the design of gated night vision devices and other gated sensors.
In accordance with the present invention, a method and system for gating a sensor are provided that substantially eliminate or reduce the disadvantages and problems associated with previously developed systems and methods.
According to one embodiment of the present invention, a method for gating a sensor is disclosed. Light is detected, and a signal corresponding to the light is generated. A gating signal is adjusted according to the signal. The adjusted gating signal is outputted to gate a sensor sensing the light.
Embodiments of the invention may provide numerous technical advantages. A technical advantage of one embodiment is that the system reduces interference associated with oscillatory ambient light under a variety of lighting conditions in order to improve a resulting image. The system can also respond to changes in the lighting conditions and adjust a gating signal in order to reduce interference. Another technical advantage of one embodiment is that the system reduces interference even if the ambient light includes multiple frequencies or does not follow a regular pattern. Another technical advantage of one embodiment is that the system may be used for a variety of gated sensor applications such as image intensifier tubes, photo multiplier tubes, biased semiconductor sensors, and biased photo voltaic sensors.
Other technical advantages are readily apparent to one skilled in the art from the following figures, descriptions, and claims.